If they are Mikuni SBN's there is no check valve on the inlet. The only way to properly test these is to block off all but one fitting on the fuel side of the carb and use that one to operate the pump.

Yes there Mikuni SBN's from a 97 785 pro, looking through the manual I cant see any check valves so I'm assuming air blowing through is nornal and i'll block it off for a retest. Thanks s bunch

Originally Posted by johnsonmtz

If they are Mikuni SBN's there is no check valve on the inlet. The only way to properly test these is to block off all but one fitting on the fuel side of the carb and use that one to operate the pump.